The present invention is particularly related to puffer-type compressed-gas circuit-interrupters of the type in which only a single pressure is utilized within the interrupting structure, and a difference of pressure for arc interruption is achieved by piston action, that is, relative movement of an operating cylinder to a piston structure. Attention may be directed to United States patents: 3,839,613 -- Tsubaki et al; 3,602,670 - Calvino Teijeiro; 3,849,616 -- Calvino Teijeiro; 3,670,124 -- Calvino Teijeiro; 3,670,125 -- Calvino Teijeiro; and 3,712,969 -- Calvino Teijeiro.
As well known by those skilled in the art, the relative motion between the movable operating cylinder assembly and the fixed piston achieves a desirable compression of gas within the compression chamber, which compressed gas is utilized during arc interruption by generally forcing the compressed high-pressure gas through a movable nozzle structure to direct the high-pressure gas flow intimately into engagement with the established arc within the movable nozzle to effect the latter's extinction.